The new picture (above) was shot at Buckingham Palace and features the 89-year-old Queen in a pink and white floral Karl Ludwig frock, sitting at her desk in her private audience room, sorting through her official dispatch box.

Queen Elizabeth's total reign is now 63 years and seven months, which beats the previous record set by Queen Victoria, who reigned for 63 years from 1837 to 1901.

The UK will mark the milestone with a series of events, including a fleet of boats that will sail along the Thames between Tower Bridge and the Houses of Parliament in London, and a four-gun salute from the HMS Belfast.